It is known to convert heavy hydrocarbons, such as those having a boiling point above about 1000xc2x0 F., such as petroleum residues into lighter hydrocarbons which are characterized by higher economic value through hydrodesulfurization (HDS), hydrodenitrogenation (HDN), carbon residue reduction (CRR), and hydrodemetallation (HDM)xe2x80x94the latter particularly including removal of nickel compounds (HDNi) and vanadium compounds (HDV).
These processes typically employ hydrotreating catalysts with specified ranges of pores having relatively small diameters (i.e., micropores) and pores having relatively large diameters (i.e., macropores). Thus, U.S. Pat. No. 5,399,259 and U.S. Pat. No. 5,435,908 disclose catalysts comprising a porous alumina support bearing 3-6 w % of Group VIII metal oxide, 14.5-24 w % of Group VI-B metal oxide, and 0-6 w % of phosphorus oxide, characterized by a Total Surface Area of 165-230 m2/g, Total Pore Volume of 0.5-0.8 cc/g, and a Pore Size Distribution (PSD) whereby less than about 5% of Total Pore Volume (TPV) is present as primary micropores of diameter less than about 80 xc3x85 and at least about 65% of the TPV is present as secondary micropores of diameter of xc2x120 xc3x85 of a Pore Mode of about 100-135 xc3x85 and about 22-29% of the TPV is present as macropores of diameter xe2x89xa7250 xc3x85.
The catalysts disclosed in theses patents are prepared by mulling an alumina powder and extruding it to form a support, calcining the support, impregnating the calcined support with the catalytic metals salts and recalcining the impregnated support.
This invention relates to a novel method of preparing catalysts and using the catalysts in converting heavy hydro-carbons. The catalysts of the present invention are prepared by mulling the salts of Group VIII, Group VI-B metals with an alumina powder, followed by extrusion and calcination, and have less than 5% of the Group VIII metal oxide in an acid extractable form; the catalyst comprising a porous alumina support containing 3-6 w % of Group VIII metal oxide, 14.5-24 w % of Group VI-B metal oxide, and 0-6 w % of phosphorus oxide, characterized by a Total Surface Area of 165-230 m2/g, Total Pore Volume of 0.81-0.98 cc/g, and a Pore Diameter Distribution whereby 22.0-36.0% of the Total Pore Volume is present as macropores of a diameter greater than 250 xc3x85, 64.0-78.0% of the Total Pore Volume is present as micropores of a diameter of less than 250 xc3x85, greater than 60% of the micropore volume is present as micropores of diameter xc2x125 xc3x85 about a pore mode by volume of 100-120 xc3x85, and less than 0.05 cc/g of micropore volume is present in micropores with diameters less than 80 xc3x85.
The method of the present invention does away with the steps of U.S. Pat. No. 5,399,259 and U.S. Pat. No. 5,435,908 that require impregnating the calcined support with the catalytic metals and with the recalcining of the impregnated support.
Since the catalysts of the instant invention are not impregnated, they do not have many of the characteristics of impregnated catalysts. Indeed, the catalysts of the instant invention typically have HDS-MAT C 0.5g @ 550xc2x0 F. values of only 10-30 and HDS-MAT relative k values of only 0.05 to 0.30.
U.S. Pat. No. 5,047,142 (Dai et al.) discloses a catalyst composition useful in the hydroprocessing of a sulfur and metal-containing feedstock comprising an oxide of nickel or cobalt and an oxide of molybdenum on a porous alumina support in such a manner that the molybdenum gradient of the catalyst has value of less than 6.0 and 15-30% of the nickel or cobalt is in an acid extractable form, and having a surface area of 150-210 m2/g, a Total Pore Volume (TPV) of 0.50-0.75 cc/g, and a pore size distribution such that less than 25% TPV is in pores having diameters of less than 100 xc3x85, 70.0-85.0% TPV is in pores having diameters of 100 xc3x85-160 xc3x85 and 1.0-15.0% TPV is in pores having diameters of greater than 250 xc3x85.
U.S. Pat. No. 4,941,964 (Dai et al.) discloses a process for the hydrotreatment of a sulfur and metal-containing feed which comprises contacting said feed with hydrogen and a catalyst in a manner such that the catalyst is maintained at isothermal conditions and is exposed to a uniform quality of feed, the catalyst comprising an oxide of a Group VIII metal, an oxide of a Group VI-B metal and 0-2.0 w % of an oxide of phosphorus on a porous alumina support, and having a surface area of 150-210 m2/g and a Total Pore Volume (TPV) of 0.50-0.75 cc/g such that 70-85% TPV is in pores having diameters of 100 xc3x85160 xc3x85 and 5.5-22.0% TPV is in pores having diameters of greater than 250 xc3x85.
U.S. Pat. No. 4,738,944 (Robinson et al.) discloses a catalyst composition useful in the hydrotreatment of hydrocarbon oils, the catalyst containing nickel and phosphorus and about 19-21.5% Mo (calculated as the oxide) on a porous refractory oxide, having a narrow pore size distribution wherein at least 10% TPV is in pores having diameters less than 70 xc3x85, at least 75% TPV is in pores having diameters between 50-110 xc3x85, at least 60% TPV is in pores having diameters within about 20 xc3x85 above and below the average pore diameter; and at most 25% TPV, most preferably less than 10% TPV, is in pores having diameters greater than 110 xc3x85.
U.S. Pat. No. 4,652,545 (Lindsley et al.) discloses a catalyst composition useful in the hydroconversion of heavy oils, the catalyst containing 0.5-5% Ni or Co and 1.8-18% Mo (calculated as the oxides) on a porous alumina support, having 15-30% of the Ni or Co in an acid extractable form, and further characterized by having a Total Pore Volume (TPV) of 0.5-1.5 cc/g with a pore diameter distribution such that (i) at least 70% TPV is in pores having 80-120 xc3x85 diameters, (ii) less than 0.03 cc/g of TPV is in pores having diameters of less than 80 xc3x85, and (iii) 0.05-0.1 cc/g of TPV is in pores having diameters of greater than 120 xc3x85.
U.S. Pat. No. 4,395,328 (Hensley, Jr. et al.) discloses a process for the hydroconversion of a hydrocarbon stream containing asphaltenes and a substantial amount of metals, comprising contacting the stream (in the presence of hydrogen) with a catalyst present in one or more fixed or ebullating beds, the catalyst comprising at least one metal which may be a Group VI-B or Group VIII metal, an oxide of phosphorus, and an alumina support, where the alumina support material initially had at least 0.8 cc/gm of TPV in pores having diameters of 0-1200 xc3x85, and at least 0.1 cc/gm of TPV is in pores having diameters of 1200-50,000, and the support material was heated with steam to increase the average pore diameter of the catalyst support material.
U.S. Pat. No. 4,341,625 (Tamm) discloses a process for hydrodesulfurizing a metal-containing hydrocarbon feedstock which comprises contacting the feedstock with a catalyst comprising at least one hydrogenation agent (i.e., Group VI-B or Group VIII metal or combinations thereof) on a porous support, the catalyst being further characterized by having a TPV of 0.5-1.1 cc/g with at least 70% TPV in pores having diameters of 80-150 xc3x85 and less than 3% TPV in pores having diameters greater than 1000 xc3x85.
U.S. Pat. No. 4,328,127 (Angevine et al.) discloses a catalyst composition for use in the hydrodemetallation-desulfurization of residual petroleum oils, the catalyst comprising a hydrogenating component (i.e., Group VI-B or Group VIII metal, or combinations thereof) on a porous support, and being further characterized by having a TPV of 0.45-1.5 cc/g with 40-75% TPV in pores having diameters of 150-200 xc3x85, and up to 5% TPV in pores having diameters of greater than 500 xc3x85.
U.S. Pat. No. 4,309,278 (Sawyer) discloses a process for the hydroconversion of a hydrocarbon feedstock comprising contacting the feedstock with hydrogen and a catalyst in a fixed bed, moving bed, ebullating bed, slurry, disperse phase, or fluidized bed reactor, where the catalyst comprises a hydrogenation component (i.e., Group VI-B or Group VIII metal) on a porous support, and is further characterized by having a TPV of 1.0-2.5 cc/g with no more than 0.05-0.20 cc/g of TPV in pores having diameters of greater than 400 xc3x85.
U.S. Pat. No. 4,305,965 (Hensley, Jr. et al.) discloses a process for the hydrotreatment of a hydrocarbon stream comprising contacting the stream with hydrogen and a catalyst, the catalyst comprising chromium, molybdenum, and at least one Group VIII metal on a porous support, and further characterized by having a TPV of 0.4-0.8 cc/g with 0-50% TPV in pores having diameters smaller than 50 xc3x85, 30-80% TPV in pores having diameters of 50-100 xc3x85, 0-50% TPV in pores having diameters of 100-150 xc3x85, and 0-20% TPV in pores having diameters greater than 150 xc3x85.
U.S. Pat. No. 4,297,242 (Hensley, Jr. et al.) discloses a 2-stage process for the catalytic hydrotreatment of hydrocarbon streams containing metal and sulfur compounds, the process comprising: (i) first contacting the feedstock with hydrogen and a demetallation catalyst comprising a Group VI-B and/or Group VIII metal; and (ii) thereafter reacting the effluent with a catalyst consisting essentially of at least one Group VI-B metal on a porous support, and having a TPV of 0.4-0.9 cc/g and a pore size distribution such that pores having diameters of 50-80 xc3x85 constitute less than 40% TPV, pores having diameters of 80-100 xc3x85 constitute 15-65% TPV, pores having diameters of 100-130 xc3x85 constitute 10-50% TPV, and pores having diameters of greater than 130 xc3x85 less than 15% TPV.
U.S. Pat. No. 4,089,774 (Oleck et al.) discloses a process for the demetallation and desulfurization of a hydrocarbon oil comprising contacting the oil with hydrogen and a catalyst, the catalyst comprising a Group VI-B metal and an iron group metal (i.e., iron, cobalt, or nickel) on a porous support, and having a surface area of 125-210 m2/g and TPV of 0.4-0.65 cc/g with at least 10% TPV in pores having diameters less than 30 xc3x85, at least 50% of pore volume accessible to mercury being in pores having diameters of 30-150 xc3x85, and at least 16.6% of pores accessible to mercury being in pores having diameters greater than 300 xc3x85.
U.S. Pat. No. 4,082,695 (Rosinski et al.) discloses a catalyst for use in the demetallation and desulfurization of petroleum oils, the catalyst comprising a hydrogenating component (i.e., cobalt and molybdenum) on a porous support, and having a surface area of 110-150 m2/g and a pore size distribution such that at least 60% of TPV is in pores having diameters of 100-200 xc3x85 and not less than 5% TPV is in pores having diameters greater than 500 xc3x85.
U.S. Pat. No. 4,066,574 (Tamm) discloses a catalyst composition useful in the hydrodesulfurization of a hydrocarbon feedstock containing organometallic compounds, the catalyst comprising Group VI-B and Group VIII metal components on a porous support, and having a TPV of 0.5-1.1 cc/g with a pore diameter distribution such that at least 70% TPV is in pores of diameters of 80-150 xc3x85 and less than 3% TPV is in pores having diameters greater than 1000 xc3x85.
U.S. Pat. No. 4,051,021 (Hamner) discloses a catalytic process for the hydrodesulfurization of a hydrocarbon feed which comprises contacting the feed with hydrogen and a catalyst, the catalyst comprising a Group VI-B and Group VIII metal on a porous support, and having a TPV of 0.3-1.0 cc/g with a pore diameter distribution such that greater than 50% TPV is in pores of diameters of 70-160 xc3x85, and pores having diameters below 70 xc3x85 and above 160 xc3x85 are minimized.
U.S. Pat. No. 4,048,060 (Riley) discloses a two-stage process for hydrodesulfurizing a heavy hydrocarbon feed which comprises: (i) contacting the feed with hydrogen and a first catalyst to produce a first hydrodesulfurized hydrocarbon product, the first catalyst comprising a Group VI-B and Group VIII metal on a porous support and having a mean pore diameter of 30-60 xc3x85; and (ii) contacting the first hydrodesulfurized hydrocarbon product with hydrogen and a second catalyst under hydrodesulfurization conditions, the second catalyst comprising a Group VI-B and Group VIII metal on a porous support and being further characterized by having a TPV of 0.45-1.50 cc/g with 0-0.5 cc/g of TPV in pores having diameters greater than 200 xc3x85, 0-0.05 cc/g of TPV in pores having diameters below 120 xc3x85, and at least 75% TPV in pores having diameters xc2x110 xc3x85 of a mean pore diameter of 140-190 xc3x85.
U.S. Pat. No. 3,876,523 (Rosinski et al.) discloses a process f or the demetalizing and desulfurizing of residual petroleum oil comprising contacting the oil with hydrogen and a catalyst, the catalyst comprising a Group VI-B and Group VIII metal on a porous support and having a pore size distribution such that greater than 60% TPV is in pores having diameters of 100-200 xc3x85, at least 5% TPV is in pores having diameters greater than 500 xc3x85, and 10% TPV or less is in pores having diameters less than 40 xc3x85, and the surface area of the catalyst is 40-150 m2/g.
U.S. Pat. No. 3,770,617 (Riley et al.) discloses a process for the desulfurization of a petroleum hydrocarbon feed comprising contacting the feed with hydrogen and a catalyst, the catalyst comprising a Group VI-B or Group VIII metal on a porous support and having greater than 50% TPV in pores of 30-80 xc3x85, less than 4% TPV in pores having diameters 200-2000 xc3x85, and at least 3% TPV in pores having diameters greater than 2000 xc3x85.
U.S. Pat. No. 3,692,698 (Riley et al.) discloses a catalyst useful in hydroprocessing of heavy feedstocks, the catalyst comprising a mixture of Group VI-B and Group VIII metals on a porous support and having a pore size distribution such that a major portion of its TPV is in pores of diameters ranging from 30-80 xc3x85, less than 4% TPV is in pores of diameters of 200-2000 xc3x85, and at least 3% TPV is in pores of diameters greater than 2000 xc3x85.
U.S. Pat. No. 4,746,419 (Peck et al) discloses catalyst compositions characterized by the presence of 0.1-0.3 cc/g of its pore volume in pores having diameter greater than 1200 xc3x85 and no more than 0.1 cc/g of its pore volume in pores having diameter greater than 4000 xc3x85.
Early petroleum distillate hydrotreating catalysts generally were monomodal catalysts with very small micropore diameters (less than about 100 xc3x85) and rather broad pore size distributions. First generation petroleum resid hydrotreating catalysts were developed by introducing a large amount of macroporosity into a distillate hydrotreating catalyst pore structure to overcome the diffusion resistance of large molecules. Such catalysts, which are considered fully bimodal HDS/HDM catalysts, are typified by U.S. Pat. Nos. 4,395,328 and 4,089,774, supra.
Another approach to developing improved catalysts for petroleum resid processing has involved enlarging the micropore diameters of essentially monomodal catalysts (having no significant macroporosities) to overcome the above described diffusion limitations. Essentially monomodal catalysts with small micropore diameters and low macroporosities designed for improved petroleum resid HDS include those disclosed in U.S. Pat. Nos. 4,738,944; 4,652,545; 4,341,625; 4,309,278; 4,305,965; 4,297,242; 4,066,574; 4,051,021; 4,048,060 (1st stage catalyst); 3,770,617; and 3,692,698, supra. Essentially monomodal catalysts with larger micropore diameters and low macroporosities designed for improved petroleum resid HDM include those disclosed in U.S. Pat. Nos. 4,328,127; 4,309,278; 4,082,695; 4,048,060 (2nd stage catalyst); and 3,876,523, supra.
A recent approach to developing improved catalysts for petroleum resid processing has involved the use of catalysts having micropore diameters intermediate between the above described monomodal HDS and HDM catalysts, as well as sufficient macroporosities so as to overcome the diffusion limitations for petroleum bottoms HDS (i.e., sulfur removal from hydrocarbon product of a hydrotreated petroleum resid having a boiling point greater than 1000xc2x0 F.) but limited macroporosities to limit poisoning of the interiors of the catalyst particles. Catalysts, with micropore diameters intermediate between the above-described monomodal HDS and HDM catalysts with limited macroporosities include those U.S. Pat. Nos. 4,941,964 and 5,047,142, supra.
However, none of the above-identified catalyst types has been found to be effective for achieving desired levels of hydroconversion of feedstock components having a boiling point greater than 1000xc2x0 F. to products having a boiling point less than 1000xc2x0 F. while simultaneously yielding a 1000xc2x0 F.+ product having a lower sulfur content.
It is a particular feature of the prior art, however, that it has not heretofore been possible to carry out hydrotreating of such feedstocks to attain desirable results as measured by conversion without undesirable formation of sediment. The charge to hydrotreating is typically characterized by a very low sediment content of 0.01 w % max.
Sediment is typically measured by testing a sample by the Shell Hot Filtration Solids Test (SHFST). See Jour. Inst. Pet. (1951) 37 pages (596-604) by Van Kerknoort et al., incorporated herein by reference. Typical prior art hydro-treating processes commonly yield Shell Hot Filtration Solids SHFS of above about 0.19 w % and as high as about 1 w % in the 650xc2x0 F.xc2x1 product recovered from the bottoms flash drum (BFD). Production of large amounts of sediment is undesirable in that it results in deposition in downstream units which in due course must be removed. This of course requires that the unit be shut down for an undesirably long period of time.
In accordance with certain of its aspects, this invention is directed to catalysts useful for hydroprocessing a charge hydrocarbon feed containing components boiling above 1000xc2x0 F., and sulfur, metals, and carbon residue which comprises:
Contacting said charge hydrocarbon feed with hydrogen at isothermal hydroprocessing conditions in the presence of a catalyst which comprises 1.1-6 w % of a Group VIII metal oxide, 5-24 w % of a Group VI-B metal oxide, and 0-2 w % of a phosphorus oxide, said catalyst being prepared by mulling the catalytic metals as salts with an alumina powder in a mulling step followed by extrusion and calcination in such a manner that less than 5% of the Group VIII metal oxide contained in the catalyst is in an acid extractable form and said catalyst having a Total Surface Area of 165-230 m2/g, a Total Pore Volume of 0.81-0.98 cc/g, and a Pore Diameter Distribution whereby 22.0-36.0% of the Total Pore Volume is present as macropores of diameter greater than 250 xc3x85, 64.0-78.0% of the Total Pore Volume is present as micropores of diameter less than 250 xc3x85, greater than 60% of the micropore volume is present as micropores of diameter 25 xc3x85 about a pore mode by volume of 100-120 xc3x85, less than 0.05 cc/g of micropore volume is present in micropores with diameters less than 80 xc3x85, thereby forming hydroprocessed product containing a decreased content of components boiling above 1000xc2x0 F. and a decreased content of sulfur, metals, and carbon residue; and
recovering said hydroprocessed product, the hydroprocessed product containing a decreased content of sediment in the portion of the hydroprocessed product boiling above 650xc2x0 F.
Suitable salts that can be used include ammonium salts such as ammonium molybdate and salts of nitric acid such as nickel nitrate. Acids that can be used include phosphoric acid, nitric acid and acetic acid.
CATALYST PROPERTIES
In general, the catalysts comprise 1.1-6 w % of a Group VIII metal oxide, 5-24 w % of a Group VI-B metal oxide, and 0-2 w % of a phosphorus oxide. Metal loadings are described in greater detail in the following table. Note that while silica and phosphorus oxide are both allowed in the Broad Range, these two catalyst components are severely restricted in the Preferred Range:
The catalysts of the present invention differ from prior art catalysts in respect of the volume of pores having a diameter of more than 600 Angstroms.